1. Field of the Invention
The present invention relates to a level shifter.
2. Description of the Related Art
In modern integrated circuit (IC) design, the logical core and the input/output unit may be powered by distinct voltages.
For example, in an IC manufactured by a 0.13 um process technique, the logical core may be powered by a power of 1.2 volts while the input/output unit is powered by a power of 3.3 volts. Because signals of the logical core operate within a first voltage range (e.g. 0˜1.2 volts) and signals of the input/output unit operate within a second voltage range (e.g. 0˜3.3 volts), a level shifter is generally required to ensure that the signals conveyed between the logical core and the input/output unit are at correct logical states.
A level shifter with correct and rapid operation and a small size is called for.